Based on your answers, some of the most likely causes of your back pain include
degenerative joint disease (also called osteoarthritis)
polymyalgia rheumatica (PMR)
disk disease
sciatica
spinal stenosis
compression fracture related to osteoporosis.
More than one of these may be present in the same person and there are other, rarer causes that could be responsible.
While over-the-counter pain medicines, a heating pad, and rest may be helpful, it is important that you see your doctor to evaluate these symptoms.